Update of previous U.S. Preventive Services Task Force (USPSTF) recommendations on screening for chlamydia (2007) and gonorrhea (2005). The USPSTF reviewed the evidence on screening for chlamydial and gonococcal infections in asymptomatic patients from studies published since its last reviews. The USPSTF also considered evidence from its previous recommendations and reviews. This recommendation applies to all sexually active adolescents and adults, including pregnant women. The USPSTF recommends screening for chlamydia in sexually active females aged 24 years or younger and in older women who are at increased risk for infection. (B recommendation) The USPSTF recommends screening for gonorrhea in sexually active females aged 24 years or younger and in older women who are at increased risk for infection. (B recommendation) The USPSTF concludes that the current evidence is insufficient to assess the balance of benefits and harms of screening for chlamydia and gonorrhea in men. (I statement).